This proposal is part of the Collaborative Studies of the Psychobilogy of the Depressive Illnesses, which are under the aegis of the Clinical Research Branch of the Division of Extramural Research Program of the NIMH. The purpose of the Collaborative Studies is to clarify the nosology of the depressive illnessess, examine the role of genetic factors in the development of depression, and explore the relationship between clinical, biological, and psychophysiological variables. The present proposal is for a pilot and feasibility study of the larger Collaborative Studies of the Psychobiology of the Depressive Illness. Two hundred patients with affective disturbance will be evaluated at the five participating facilities using the battery of initial assessment procedures that will be used in the larger study. Data from this study will be analyzed in terms of the hypotheses of the larger study, the relationship between the assessments, and the interjudge reliabilities of the clinical procedures.